Tool-holder.



No. 636,74l. Patented Nov. l4, I899. J. A TRONG.

T0 OLDER.

lication filed July 10, 1899 744M1 0, fmxenfar:

UNITED STATES PATENT (drricn JAMES ARMSTRONG, or CHICAGO, ILLINOIS-:1

TooL-HoLoEa.

s'rscltimm forming part of Letters Patent No. 636,741, dated. lvbvmbei 14, 1899.

Application filed July 10, 1899. $erla1No. 723,268- (No model.)

To all whom away concern: p, y 1 'Be it known that. I,- JAMES ARMSTRONG, a

citizen of the United States, and a resident of.

Chicago, countyof Cook, and State of Illinois, have invented certain new and useful Imrovements in Tool-Holders, of which the folowing is a specification, and which are illustrated in the accompanying drawings, forming a part thereof.

This invention relates particularly to hold- 1 ers for cutting-off tools and which constitute Q a stock for a hardened bit-piece.

The object of the invention is to provide a 1 holder for this class of tools which will be simple, strong, and easy of adjustment and i which will as securely hold a short bit-piece as a long one.

This object is attained in the construction hereinafter fully described 1 and which is illustrated in the accompanying 1 bar is thinner at its lower edge than at its upper edge, so as to provide clearance-space -as it enters the material operated upon.

The body or stock B of the holder is a bar adapted to enter the tool-post socket, and being preferably drop-forged steel, and having a channel '1) along one side of the same width as and adapted to receive the bit-piece A. The bottom of this channel is inclined-that is to say, the channel is of greater depth at one side than the other, the pitch or inclination corresponding to that of theside of the bit, so that the median plane of the bit piece is parallel with that'ofthe stock when the former is within the channel 12.

At its forward end the stock B is beveled from its lower or rearward side backwardly, so that while considerably removed from the blade at of the bit-piece it projects forwardly along the rearward edge ofrthe latter to bring the point of support near to the work. At both its upper or advance and lower or rearward sides the stock is provided .with aboss or. enlargement O D, and within each of these bosses. is formed alcounterbored aperture to receive the retaining-bolts E F. Each of the boss-apertures crosses one of the sides ofithe channel I), and its enlarged end is at the channel'ed side of the stock, so that the bolts-may be provided with large heads '6 f, which are laterally slotted at G H to receive the edges of the bit-piece A, the slots being of such depth that their bottoms will coincide with the side walls of the channel 19. Furthermore, the slots have their outer walls inclined to the axis of the bolt to correspond with the pitch of the side of the bit-piece, so that when the parts are assembled and the nuts M .0 applied to the ends of the bolts the slot-walls bear fairly upon the bit-piece. The bolts E F are made of hardened steel.

I am aware that there has been made a holder for tools of this character with a channel for the bit-piece to rest in; but it relied upon the channel edge to supply the seat for the bit-piece and receive substantially the entire burden of the work. As the rearward edge of the bit-piece is quite thin and the piece is of much harder material than the stock, the seat in the latter would give way under the severe pressure to which it was subjected.

By forming the bottom of the channel inclined and clamping the bit-piece securely against it and providing the bit with a' seat of hardened steel in the bolt-heads I am able not only to distribute the burden, but provide a seat into which the thin edge of the bit can not sink. It will be seen that in order to conform to the inclination of the side of the bit the outer wall of the slot of the bolt E is undercut, so that when 'the nut is turned up tightly on this bolt the strain of the work is resisted by the tensile strength of the bolt, as the tapering form of the bit tends to lift the bolt out of its socket by a wedge action. The bolt-heads are of suflicient size to afiord ample bearing laterally against the soft-metal walls of their sockets to so distribute the pressure that these walls will not yield under would constitute a decided improvement over tool-holders of this character heretofore in use.

I claim as my invention- 1. In a tool of the class described, in combination, a bit-piece wedge-shaped in crosssection, a stock having a longitudinal channel along one of its sides to receive the bitpiece, and having bolt-apertures overlapping both sides of the channel; and bolts adapted to such apertures, having lateral slots registering with the channel, such slots conforming in cross-section with the shape of the bitpiece.

2. In a tool of the class described, in combination, a stock having a longitudinal channel in one side to receive a bit-piece wedgeshaped in cross-section, and having a bolt-aperture overlapping one edge of its channel; and a bolt adapted to such aperture and having a lateral slot to receive the bit-piece, such slot conformingin cross-section with the shape of the bit-piece.

3. In a tool of the class described, in conibination, the bit-piece wedge-shaped in crosssection, the channeled stock having the bosses at its forward end, and counterbored apertures therethrough as described, the hardened bolts adapted to such apertures and having lateral slots registering with the channel, such slots conforming in cross-section with the shape of the bit-piece.

4. In a tool of the class described, in combination, a Wedge-shaped bit-piece, a stock channeled to receive the bit-piece and having a bolt-socket intersecting the upper edge of the channel; and a screw-bolt adapted to such socket and having a lateral lip engaging the thicker edge of the bit-piece; the engaging face of the lip being inclined to correspond with the incline of the side of the bit.

JAMES ARMSTRONG.

Witnesses:

THOMAS CLANCY, JOHN M. CLANCY. 

